The present invention relates to structured cabling systems and more particularly to structured cabling systems used in local area networks.
Structured cabling systems are well known for use in institutional infrastructure. Such systems provide a standardized yet flexible platform for a dynamic communications environment. Typically structure cabling systems employ twisted copper pairs which are installed in accordance with predetermined criteria. Structured cabling systems are conventionally employed for telephone, data communications, as well as for alarms, security and access control applications.
The present invention seeks to provide an enhanced structured cabling system and local area network employing such a system.
There is thus provided in accordance with a preferred embodiment of the present invention a local area network including a hub, a plurality of nodes, communication cabling connecting the plurality of nodes to the hub for providing data communication; and a power supply distributor operative to provide at least some operating power to at least some of the plurality of nodes via the communication cabling.
Further in accordance with a preferred embodiment of the present invention the communication cabling includes at least part of a structured cabling system.
Still further in accordance with a preferred embodiment of the present invention the power supply distributor is located within the hub.
Additionally in accordance with a preferred embodiment of the present invention the power supply distributor is located outside the hub.
Moreover in accordance with a preferred embodiment of the present invention the power supply distributor is located partially within the hub and partially outside the hub.
Still further in accordance with a preferred embodiment of the present invention the operating power supplied by said power supply distributor to at least some of said plurality nodes via said communication cabling includes backup power.
Additionally in accordance with a preferred embodiment of the present invention the hub includes a data communication concentrator, the power supply distributor includes a combiner, and the communication cabling connects the data communication concentrator via the combiner to the nodes.
Sill further in accordance with a preferred embodiment of the present invention the hub includes a data communication concentrator and wherein the power supply distributor is also located within the hub.
Additionally in accordance with a preferred embodiment of the present invention the hub includes a data communication concentrator and wherein the power supply distributor is also located within the hub and includes a power supply and a combiner, the combiner coupling power from the power supply to the communication cabling which also carries data from the data communication concentrator.
Preferably the data communication concentrator comprises a LAN switch which functions as a data communication switch/repeater.
Additionally in accordance with a preferred embodiment of the present invention the plurality of nodes includes at least one of the following types of nodes: wireless LAN access points, emergency lighting system elements, paging loudspeakers, CCTV cameras, alarm sensors, door entry sensors, access control units, laptop computers, IP telephones, hubs, switches, routers, monitors and memory backup units for PCs and workstations.
Still further in accordance with a preferred embodiment of the present invention the hub includes a data communication concentrator the power supply distributor includes a combiner and a power supply, the communication cabling connects the data communication concentrator via the combiner to the nodes, and the combiner includes a plurality of couplers, each of which is connected to an output of the power supply.
Further in accordance with a preferred embodiment of the present invention the hub includes a data communication concentrator, the power supply distributor includes a combiner and a power supply, the communication cabling connects the data communication concentrator via the combiner to the nodes, and the combiner comprises a plurality of couplers and a plurality of filters, each coupler being connected via a filter to an output of the power supply.
Still further according to a preferred embodiment of the present invention the hub includes a data communication concentrator, the power supply distributor includes a combiner and a power supply, the communication cabling connects the data communication concentrator via the combiner to the nodes, and the combiner includes a plurality of couplers and a plurality of filters and a plurality of smart power allocation and reporting circuits (SPEARs), each coupler being connected via a filter and a SPEAR to an output of the power supply.
Moreover in accordance with a preferred embodiment of the present invention the hub includes a data communication concentrator, the power supply distributor includes a combiner and a power supply, and the power supply includes a power failure backup facility.
Additionally or alternatively the hub includes a data communication concentrator; the power supply distributor includes a combiner and a power supply, the communication cabling connects the data communication concentrator via the combiner to the nodes, and the combiner comprises a plurality of couplers and a plurality of filters, each coupler being connected via a filter to an output of the power supply.
Moreover according to a preferred embodiment of the present invention the hub includes a data communication concentrator, the power supply distributor includes a combiner and a power supply, the communication cabling connects the data communication concentrator via the combiner to the nodes, and the combiner includes a plurality of couplers and a plurality of filters and a plurality of smart power allocation and reporting circuits (SPEARs), each coupler being connected via a filter and a SPEAR to an output of the power supply.
Preferably the hub includes a data communication concentrator, the power supply distributor includes a combiner and a power supply, the communication cabling connects the data communication concentrator via the combiner to the nodes, and the combiner includes a plurality of couplers and a plurality of filters, each coupler being connected via a filter to an output of the power supply.
Additionally or alternatively the hub includes a data communication concentrator, the power supply distributor includes a combiner and a power supply, the communication cabling connects the data communication concentrator via the combiner to the nodes, and the combiner comprises a plurality of couplers and a plurality of filters and a plurality of smart power allocation and reporting circuits (SPEARs), each coupler being connected via a filter and a SPEAR to an output of the power supply.
Preferably the hub includes a data communication concentrator, the power supply distributor includes a combiner and a power supply, the communication cabling connects the data communication concentrator via the combiner to the nodes, and the combiner includes a plurality of couplers and a plurality of filters, each coupler being connected via a filter to an output of the power supply.
Additionally or alternatively the hub includes a data communication concentrator, the power supply distributor includes a combiner and a power supply, the communication cabling connects the data communication concentrator via the combiner to the nodes, and the combiner includes a plurality of couplers and a plurality of filters and a plurality of smart power allocation and reporting circuits (SPEARs), each coupler being connected via a filter and a SPEAR to an output of the power supply.
Further in accordance with a preferred embodiment of the present invention the power supply distributor is operative to provide electrical power along the communication cabling without unacceptable degradation of the digital communication.
Still further in accordance with a preferred embodiment of the present invention the communication cabling comprises at least one twisted wire pair connected to each node and wherein power is transmitted over a twisted wire pair along which data is also transmitted.
Preferably the hub includes a data communication concentrator, the power supply distributor includes a power supply interface and a power supply, the communication cabling connects the data communication concentrator via the power supply interface to the nodes, and power supply interface includes a plurality of filters and a plurality of smart power allocation and reporting circuits (SPEARs), each filter being connected via a SPEAR to an output of the power supply.
Additionally in accordance with a preferred embodiment of the present invention the communication cabling comprises at least two twisted wire pairs connected to each node and wherein power is transmitted over a twisted wire pair different from that along which data is transmitted.
Preferably the hub includes a data communication concentrator, the power supply distributor includes a power supply interface and a power supply, the communication cabling connects the data communication concentrator via the power supply interface to the nodes, and the power supply interface includes a plurality of filters and a plurality of smart power allocation and reporting circuits (SPEARs), each filter being connected via a SPEAR to an output of the power supply.
Still further in accordance with a preferred embodiment of the present invention the hub includes a data communication concentrator, the power supply distributor includes a combiner and a power supply, the communication cabling connects the data communication concentrator via the combiner to the nodes, the combiner includes a plurality of couplers and a plurality of filters and a plurality of smart power allocation and reporting circuits (SPEARs), each coupler being connected via a filter and a SPEAR to an output of the power supply, and each coupler has at least two ports, one of which is connected to a port of the data communication concentrator and the other of which is connected, via communication cabling, to one of the plurality of nodes.
There is also provided in accordance with a preferred embodiment of the present invention a local area network node for use in a local area network including a hub, a plurality of nodes, communication cabling connecting the plurality of nodes to the hub for providing digital communication and a power supply distributor operative to provide at least some operating power to at least some of the plurality of nodes via the hub and the communication cabling, the local area network node including a communications cabling interface receiving both power and data and separately providing power to a node power input and data to a node data input.
Further in accordance with a preferred embodiment of the present invention the communications cabling interface is internal to at least one of the plurality of nodes.
Still further in accordance with a preferred embodiment of the present invention the communications cabling interface is external to at least one of the plurality of nodes.
Additionally in accordance with a preferred embodiment of the present invention the power supply distributor is operative to provide electrical power along the communication cabling without unacceptable degradation of the digital communication.
Still further in accordance with a preferred embodiment of the present invention the communication cabling includes at least one twisted wire pair connected to each node and wherein power is transmitted over a twisted wire pair along which data is also transmitted.
Additionally in accordance with a preferred embodiment of the present invention the communication cabling includes at least two twisted wire pairs connected to each node and wherein power is transmitted over a twisted wire pair different from that along which data is transmitted.
Preferably the power supply distributor is operative to provide electrical power along the communication cabling without unacceptable degradation of the digital communication.
Additionally the communication cabling may include at least one twisted wire pair connected to each node and wherein power is transmitted over a twisted wire pair along which data is also transmitted.
Further more in accordance with a preferred embodiment of the present invention the communication cabling includes at least two twisted wire pairs connected to each node and wherein power is transmitted over a twisted wire pair different from that along which data is transmitted.
Preferably the power supply distributor is operative to provide electrical power along the communication cabling without unacceptable degradation of the digital communication.
Further in accordance with a preferred embodiment of the present invention the communication cabling includes at least one twisted wire pair connected to each node and wherein power is transmitted over a twisted wire pair along which data is also transmitted.
Still further in accordance with a preferred embodiment of the present invention the communication cabling includes at least two twisted wire pairs connected to each node and wherein power is transmitted over a twisted wire pair different from that along which data is transmitted.
Moreover in accordance with a preferred embodiment of the present invention the hub includes a data communication concentrator, the power supply distributor includes a combiner, a management and control unit and a power supply, the communication cabling connects said data communication concentrator via the combiner to the node, the combiner includes a plurality of couplers and a plurality of filters and a plurality of smart power allocation and reporting circuits (SPEARs), each coupler being connected via a filter and a SPEAR to an output of said power supply, and the SPEAR is operative to report to the management and control unit the current consumption of a node connected thereto.
Further in accordance with a preferred embodiment of the present invention the hub includes a data communication concentrator, the power supply distributor includes a combiner and a power supply, the communication cabling connects the data communication concentrator via the combiner to the nodes, the combiner comprises a plurality of couplers and a plurality of filters and a plurality of smart power allocation and reporting circuits (SPEARs), each coupler being connected via a filter and a SPEAR to an output of the power supply, and the SPEAR is operative to limit the maximum current supplied to a node connected thereto.
Alternatively according to a preferred embodiment of the present invention the hub includes a data communication concentrator, the power supply distributor includes a combiner and a power supply, the communication cabling connects the data communication concentrator via the combiner to the nodes, the combiner includes a plurality of couplers and a plurality of filters and a plurality of smart power allocation and reporting circuits (SPEARs), each coupler being connected via a filter and a SPEAR to an output of the power supply, and the SPEAR is operative to automatically disconnect a node connected thereto displaying an overcurrent condition following elapse of a programmably predetermined period of time.
Additionally in accordance with a preferred embodiment of the present invention the hub includes a data communication concentrator, the power supply distributor includes a combiner and a power supply, the communication cabling connects the data communication concentrator via the combiner to the nodes, the combiner includes a plurality of couplers and a plurality of filters and a plurality of smart power allocation and reporting circuits (SPEARs), each coupler being connected via a filter and a SPEAR to an output of the power supply, and the SPEAR is operative to automatically disconnect power from a node connected thereto displaying an overcurrent condition following elapse of a programmably predetermined period of time and to automatically reconnect the node to power thereafter when it no longer displays the overcurrent condition.
Moreover in accordance with a preferred embodiment of the present invention the hub includes a data communication concentrator, the power supply distributor includes a combiner and a power supply, the communication cabling connects said data communication concentrator via the combiner to the nodes, the combiner includes a plurality of couplers and a plurality of filters and a plurality of smart power allocation and reporting circuits (SPEARs), each coupler being connected via a filter and a SPEAR to an output of the power supply, and the SPEAR includes a current sensor which receives a voltage input Vin from a power supply and generates a signal which is proportional to the current passing therethrough, and a multiplicity of comparators receiving the signal from the current sensor and also receiving a reference voltage Vref from respective reference voltage sources.
Preferably the reference voltage sources are programmable reference voltage sources and receive control inputs from management and control circuits.
Additionally the outputs of the multiplicity of comparators may be supplied to a current limiter and switch which receives input voltage Vin via the current sensor and provides a current-limited voltage output Vout.
Furthermore the outputs of the comparators are supplied to management and control circuits to serve as monitoring inputs providing information regarding the DC current flowing through the SPEAR.
Additionally in accordance with a preferred embodiment of the present invention the hub includes a data communication concentrator, the power supply distributor includes a combiner and a power supply, the communication cabling connects the data communication concentrator via the combiner to the nodes, and the combiner includes a plurality of couplers each of which includes at least a pair of transformers, each having a center tap at a secondary thereof via which the DC voltage is fed to each wire of a twisted pair connected thereto.
Further in accordance with a preferred embodiment of the present invention the hub includes a data communication concentrator, the power supply distributor includes a combiner and a power supply, the communication cabling connects the data communication concentrator via the combiner to the nodes, and the combiner includes a plurality of couplers each of which includes at least one transformer, which is characterized in that it includes a secondary which is split into two separate windings and a capacitor which is connected between the two separate windings and which effectively connects the two windings in series for high frequency signals, but effectively isolates the two windings for DC.
Still further in accordance with a preferred embodiment of the present invention the hub includes a data communication concentrator, the power supply distributor includes a combiner a power supply, the communication cabling connects the data communication concentrator via the combiner to the nodes, and the combiner includes a pair of capacitors which effectively block DC from reaching the data communication concentrator.
Still further in accordance with a preferred embodiment of the present invention the hub includes a data communication concentrator, the power supply distributor includes a combiner and a power supply, the communication cabling connects the data communication concentrator via the combiner to the nodes, and the combiner comprises two pairs of capacitors which effectively block DC from reaching the data communication concentrator.
Additionally in accordance with a preferred embodiment of the present invention the hub includes a data communication concentrator, the power supply distributor includes a combiner and a power supply, the communication cabling connects the data communication concentrator via the combiner to the nodes, and the combiner includes a self-balancing capacitor-less and transformer-less common mode coupling circuit.
Preferably the communications cabling interface includes a separator and a pair of transformers, each having a center tap at a primary thereof via which the DC voltage is extracted from each wire of a twisted pair connected thereto.
Additionally or alternatively the communications cabling interface includes a separator including at least one transformer, which is characterized in that it includes a primary which is split into two separate windings and a capacitor which is connected between the two separate windings and which effectively connects the two windings in series for high frequency signals, but effectively isolates the two windings for DC.
Furthermore the communications cabling interface includes a separator comprising a pair of capacitors which effectively block DC from reaching a data input of a node connected thereto.
Additionally in accordance with a preferred embodiment of the present invention the communications cabling interface includes a separator comprising two pairs of capacitors which effectively block DC from reaching a data input of a node connected thereto.
Additionally or alternatively the communications cabling interface includes a separator includes a self-balancing capacitor-less and transformer-less common mode coupling circuit.
There is further provided in accordance with a preferred embodiment of the present invention a local area network including a hub, a plurality of nodes, a communication cabling connecting said plurality of nodes to the hub for providing data communication, and a power supply distributor operative to provide at least some operating power to at least some of the plurality of nodes via the communication cabling, the power supply distributor including power management functionality.
Preferably the power supply distributor includes a power management and control unit which monitors and controls the power supplied to various nodes via the communications cabling.
Additionally in accordance with a preferred embodiment of the present invention the power supply distributor includes a management workstation which is operative to govern the operation of the power management and control unit.
Preferably the management workstation governs the operation of multiple power management and control units.
Moreover in accordance with a preferred embodiment of the present invention the power management and control unit communicates with various nodes via a data communication concentrator thereby to govern their current mode of power usage.
Further in accordance with a preferred embodiment of the present invention the power management and control unit communicates with various nodes via control messages which are decoded at the nodes and are employed for controlling whether full or partial functionality is provided thereat.
Still further in accordance with a preferred embodiment of the present invention the power management and control unit senses that mains power to said power supply distributor is not available and sends a control message to cause nodes to operate in a backup or reduced power mode.
Preferably the node includes essential circuitry, which is required for both full functionality and reduced functionality operation, and non-essential circuitry, which is not required for reduced functionality operation.
There is also provided with yet another preferred embodiment of the present invention a local area network power supply distributor for use in a local area network including a hub, a plurality of nodes and communication cabling connecting the plurality of nodes to a hub for providing digital communication therebetween, the power supply distributor being operative to provide at least some operating power to at least some of said plurality of nodes via the communication cabling.
Further in accordance with a preferred embodiment of the present invention the supply distributor is located within the hub.
Still further in accordance with a preferred embodiment of the present invention the power supply distributor is located outside the hub. Alternatively the power supply distributor is located partially within the hub and partially outside the hub.
Additionally in accordance with a preferred embodiment of the present invention the operating power supplied by the power supply distributor to at least some of the plurality nodes via the communication cabling includes backup power.
Still further in accordance with a preferred embodiment of the present invention the hub includes a data communication concentrator, the power supply distributor includes a combiner, and the communication cabling connects the data communication concentrator via the combiner to the nodes.
Moreover in accordance with a preferred embodiment of the present invention the hub includes a data communication concentrator and wherein the power supply distributor is also located within the hub.
Still further in accordance with a preferred embodiment of the present invention the hub includes a data communication concentrator and wherein said power supply distributor is also located within the hub and includes a power supply and a combiner, the combiner coupling power from the power supply to the communication cabling which also carries data from the data communication concentrator.
Preferably the combiner includes a plurality of couplers, each of which is connected to an output of the power supply.
Additionally in accordance with a preferred embodiment of the present invention the combiner includes a plurality of couplers and a plurality of filters, each coupler being connected via a filter to an output of the power supply.
Furthermore the combiner may also include a plurality of couplers and a plurality of filters and a plurality of smart power allocation and reporting circuits (SPEARs), each coupler being connected via a filter and a SPEAR to an output of the power supply.
Additionally in accordance with a preferred embodiment of the present invention the power supply distributor includes a power supply, and the power supply includes a power failure backup facility.
Still further in accordance with a preferred embodiment of the present invention the combiner includes a plurality of couplers and a plurality of filters, each coupler being connected via a filter to an output of the power supply.
Preferably the combiner includes a plurality of couplers and a plurality of filters and a plurality of smart power allocation and reporting circuits (SPEARs), each coupler being connected via a filter and a SPEAR to an output of the power supply.
Moreover in accordance with a preferred embodiment of the present invention the combiner includes a plurality of couplers and a plurality of filters, each coupler being connected via a filter to an output of a power supply.
Additionally the combiner may also include a plurality of couplers and a plurality of filters and a plurality of smart power allocation and reporting circuits (SPEARs), each coupler being connected via a filter and a SPEAR to an output of the power supply.
Furthermore the combiner may also include a plurality of couplers and a plurality of filters, each coupler being connected via a filter to an output of a power supply.
Moreover in accordance with a preferred embodiment of the present invention the power supply distributor is operative to provide electrical power along the communication cabling without unacceptable degradation of the digital communication.
Further in accordance with a preferred embodiment of the present invention the communication cabling includes at least one twisted wire pair connected to each node and wherein power is transmitted over a twisted wire pair along which data is also transmitted.
Preferably the power supply distributor includes a power supply interface and a power supply, the communication cabling connects the data communication concentrator via the power supply interface to the nodes, and the power supply interface includes a plurality of filters and a plurality of smart power allocation and reporting circuits (SPEARs), each filter being connected via a SPEAR to an output of the power supply.
Additionally in accordance with a preferred embodiment of the present invention the communication cabling includes at least two twisted wire pairs connected to each node and wherein power is transmitted over a twisted wire pair different from that along which data is transmitted.
Moreover in accordance with a preferred embodiment of the present invention the hub includes a data communication concentrator, the power supply distributor includes a power supply interface and a power supply, the communication cabling connects the data communication concentrator via the power supply interface to said nodes, and the power supply interface includes a plurality of filters and a plurality of smart power allocation and reporting circuits (SPEARs), each filter being connected via a SPEAR to an output of the power supply.
Still further in accordance with a preferred embodiment of the present invention the hub includes a data communication concentrator, the power supply distributor includes a combiner and a power supply, the communication cabling connects the data communication concentrator via the combiner to the nodes, the combiner includes a plurality of couplers and a plurality of filters and a plurality of smart power allocation and reporting circuits (SPEARs), each coupler being connected via a filter and a SPEAR to an output of the power supply, and each coupler has at least two ports, one of which is connected to a port of the data communication concentrator and the other of which is connected, via communication cabling, to one of the plurality of nodes.
Additionally in accordance with a preferred embodiment of the present invention the hub includes a data communication concentrator, the power supply distributor includes a combiner, a management and control unit and a power supply, the communication cabling connects said data communication concentrator via the combiner to the nodes, the combiner includes a plurality of couplers and a plurality of filters and a plurality of smart power allocation and reporting circuits (SPEARs), each coupler being connected via a filter and a SPEAR to an output of the power supply, and the SPEAR is operative to report to the management and control unit the current consumption of a node connected thereto.
Still further in accordance with a preferred embodiment of the present invention the hub includes a data communication concentrator, the power supply distributor includes a combiner and a power supply, the communication cabling connects the data communication concentrator via the combiner to the nodes, the combiner includes a plurality of couplers and a plurality of filters and a plurality of smart power allocation and reporting circuits (SPEARs), each coupler being connected via a filter and a SPEAR to an output of the power supply, and the SPEAR is operative to limit the maximum current supplied to a node connected thereto.
Still further in accordance with a preferred embodiment of the present invention the hub includes a data communication concentrator, the power supply distributor includes a combiner and a power supply, the communication cabling connects the data communication concentrator via the combiner to the nodes, the combiner includes a plurality of couplers and a plurality of filters and a plurality of smart power allocation and reporting circuits (SPEARs), each coupler being connected via a filter and a SPEAR to an output of the power supply, and the SPEAR is operative to automatically disconnect a node connected thereto displaying an overcurrent condition following elapse of a programmably predetermined period of time.
Additionally in accordance with a preferred embodiment of the present invention the hub includes a data communication concentrator, the power supply distributor includes a combiner and a power supply, the communication cabling connects the data communication concentrator via the combiner to the nodes, the combiner includes a plurality of couplers and a plurality of filters and a plurality of smart power allocation and reporting circuits (SPEARs), each coupler being connected via a filter and a SPEAR to an output of the power supply, and the SPEAR is operative to automatically disconnect power from a node connected thereto displaying an overcurrent condition following elapse of a programmably predetermined period of time and to automatically reconnect the node to power thereafter when it no longer displays the overcurrent condition.
Still further in accordance with a preferred embodiment of the present invention the hub includes a data communication concentrator, the power supply distributor includes a combiner and a power supply, the communication cabling connects the data communication concentrator via the combiner to the nodes, the combiner includes a plurality of couplers and a plurality of filters and a plurality of smart power allocation and reporting circuits (SPEARs), each coupler being connected via a filter and a SPEAR to an output of the power supply, and the SPEAR includes a current sensor which receives a voltage input Vin from a power supply and generates a signal which is proportional to the current passing therethrough, and a multiplicity of comparators receiving the signal from the current sensor and also receiving a reference voltage Vref from respective reference voltage sources.
Preferably the reference voltage sources are programmable reference voltage sources and receive control inputs from management and control circuits.
Additionally the outputs of the multiplicity of comparators may be supplied to a current limiter and switch which receives input voltage Vin via the current sensor and provides a current-limited voltage output Vout.
Furthermore the outputs of the comparators may be supplied to management and control circuits to serve as monitoring inputs providing information regarding the DC current flowing through the SPEAR.
Still further in accordance with a preferred embodiment of the present invention the hub includes a data communication concentrator, the power supply distributor includes a combiner and a power supply, the communication cabling connects the data communication concentrator via the combiner to the nodes, and the combiner includes plurality of couplers each of which includes at least a pair of transformers, each having a center tap at a secondary thereof via which the DC voltage is fed to each wire of a twisted pair connected thereto.
Additionally in accordance with a preferred embodiment of the present invention the hub includes a data communication concentrator, the power supply distributor includes a combiner and a power supply, the communication cabling connects the data communication concentrator via the combiner to the nodes, and the combiner includes a plurality of couplers each of which includes at least one transformer, which is characterized in that it includes a secondary which is split into two separate windings and a capacitor which is connected between the two separate windings and which effectively connects the two windings in series for high frequency signals, but effectively isolates the two windings for DC.
Further in accordance with a preferred embodiment of the present invention the hub includes a data communication concentrator, the power supply distributor includes a combiner and a power supply, the communication cabling connects the data communication concentrator via the combiner to the nodes, and the combiner includes a pair of capacitors which effectively block DC from reaching the data communication concentrator.
Still further in accordance with a preferred embodiment of the present invention the hub includes a data communication concentrator, the power supply distributor includes a combiner and a power supply, the communication cabling connects the data communication concentrator via the combiner to the nodes, and the combiner comprises two pairs of capacitors which effectively block DC from reaching the data communication concentrator.
Additionally in accordance with a preferred embodiment of the present invention the hub includes a data communication concentrator, the power supply distributor includes a combiner and a power supply, the communication cabling connects the data communication concentrator via the combiner to the nodes, and the combiner comprises a self-balancing capacitor-less and transformer-less common mode coupling circuit.
Preferably the power supply distributor includes power management functionality.
Additionally the power supply distributor may include a power management and control unit which monitors and controls the power supplied to various nodes via the communications cabling.
Furthermore the power supply distributor may include a management workstation which is operative to govern the operation of said power management and control unit.
Furthermore in accordance with a preferred embodiment of the present invention the management workstation governs the operation of multiple power management and control units.
Preferably the power management and control unit communicates with various nodes via a data communication concentrator thereby to govern their current mode of power usage.
Additionally in accordance with a preferred embodiment of the present invention the power management and control unit communicates with various nodes via control messages which are decoded at the nodes and are employed for controlling whether full or partial functionality is provided thereat.
Additionally the power management and control unit senses that mains power to the power supply distributor is not available and sends a control message to cause nodes to operate in a backup or reduced power mode.
Furthermore the node includes essential circuitry, which is required for both full functionality and reduced functionality operation, and non-essential circuitry, which is not required for reduced functionality operation.